from .forms import EmailPostForm
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
from django.shortcuts import render, get_object_or_404
from django.core.mail import send_mail
from .models import Post
from .forms import EmailPostForm, CommentForm
from taggit.models import Tag
from django.db.models import Count
# 导入Django提供的搜索向量类
from django.contrib.postgres.search import SearchVector
from .forms import EmailPostForm, CommentForm, SearchForm

# Create your views here.
def post_list(request, tag_slug=None):
    posts = Post.published.all()
    paginator = Paginator(posts, 3)
    page = request.GET.get('page')
    tag = None
 # 如果请求中有tag_slug，则获取标签并按标签过滤文章数据
    if tag_slug:
 # 获取标签
        tag = get_object_or_404(Tag, slug=tag_slug)
 # 按标签过滤文章
    posts = posts.filter(tags=tag)
    try:
        posts = paginator.page(page)
    except PageNotAnInteger:
        posts = paginator.page(1)
    except EmptyPage:
        posts = paginator.page(paginator.num_pages)
    return render(request,
                    'blog/post/list.html',
                    {'posts': posts,
                     'page': page})

def post_detail(request, year, month, day, post):
    post = get_object_or_404(Post, slug=post, status='published',
                            publish__year=year,
                            publish__month=month,
                            publish__day=day)
    new_comment = None
    comments = post.comments.filter(active=True)
    post_tags_ids = post.tags.values_list('id', flat=True)
    similar_posts = Post.published.filter(tags__in=post_tags_ids).exclude(id=post.id)
    similar_posts = similar_posts.annotate(same_tags=Count('tags')).order_by('-same_tags','-publish')[:4]
    

    if request.method == 'POST':
        comment_form = CommentForm(data=request.POST)
        if comment_form.is_valid():
            new_comment = comment_form.save(commit=False)
            new_comment.post = post
            new_comment.save()
    else:
        comment_form = CommentForm()
    return render(request,
                    'blog/post/detail.html',
                    {'post': post,
                    'comments': comments,
                    'new_comment': new_comment,
                    'comment_form': comment_form,
                    'similar_posts': similar_posts})
def post_share(request, post_id):
    post = get_object_or_404(Post, id=post_id, status='published')
 # 设置发送状态为未发送
    sent = False
 # 如果请求是POST表示有提交表单
    if request.method == 'POST':
 # 通过EmailPostForm表单类获取请求中的表单数据后保存到form中
        form = EmailPostForm(request.POST)
 # 如果表单数据验证通过则发送邮件并将状态设置为已发送
        if form.is_valid():
            cd = form.cleaned_data
            post_url = request.build_absolute_uri(post.get_absolute_url())
            subject = f"{cd['name']} recommends you read " \
                        f"{post.title}"
            message = f"Read {post.title} at {post_url}\n\n" \
                        f"{cd['name']}\'s comments: {cd['comments']}"
            send_mail(subject, message, '3253791848@qq.com',
                        [cd['to']])
 # 发送状态设置为真
            sent = True
    else:
 # 如果表单数据验证未通过将表单设置为空
        form = EmailPostForm()
 # 渲染分享文章模板，并将文章、表单、发送状态信息传递给文章分享模板
    return render(request, 'blog/post/share.html', {'post': post,
                                                    'form': form,
                                                    'sent': sent})


def post_search(request):
  form = SearchForm()
  query = None
  results = []
 # 如果请求中有query字段则获取表单中的数据进行处理
  if 'query' in request.GET:
 # 获取表单
    form = SearchForm(request.GET)
 # 如果表单中的数据验证通过，即有效，则获取并处理
    if form.is_valid():
 # 获取搜索内容保存下来
     query = form.cleaned_data['query']
 # 根据标题和正文字段构建搜索向量并生成搜索字段，再根据搜索内容筛选出匹配内容保存
    results = Post.published.annotate(
      search=SearchVector('title', 'body')
      ).filter(search=query)
 # 将搜索结果渲染到搜索模板并返回
    return render(request,
                  'blog/post/search.html', {
                  'form': form,
                  'query': query,
                  'results': results
                })
